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Abstract
Polymer electrolyte membrane (PEM) fuel cells have the potential to replace fossil fuel sources in both automotive and auxiliary stationary power generation applications. Increased implementation of fuel cells would decrease dependence on oil and reduce greenhouse gas emissions. However, a major obstacle preventing widespread adoption of fuel cells is cost. The two largest contributors to fuel cell costs are platinum catalyst loading and fuel cell power density. The general strategy for increasing power density and decreasing costly catalyst loading remains unchanged regardless of the catalyst used, i.e., to run the fuel cell at higher temperatures and pressures. Present-day automotive fuel cells typically operate over a temperature range of 50-90°C and pressures up to 3 atm. Increasing temperature and pressure allows for reduced catalyst loading and higher voltage output from the fuel cell. These harsher operating conditions require new membrane materials for thermal and water management. This review provides a summary of a variety of humidification membrane materials, both existing and under development, in order to identify a humidification membrane material capable of operating at higher temperature and pressure conditions to increase fuel cell efficiency and lower the humidification.
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